This invention relates generally to the area of portable receivers with time of day clocks. In particular this invention relates to a portable receiver receiving a signal indicating a location, the portable receiver determining a time zone corresponding to the location and adjusting the time of day clock in response thereto.
The features of portable receivers such as paging receivers have expanded to include time of day clocks. Additionally, the use of paging receivers within nation wide systems having location signals has become a valuable tool for the traveling business person. As the traveling business person travels between time zones, the time displayed on the clock must be adjusted. This constant adjustment in the course of traveling can become a tedious operation, and if neglected can result in disastrous conclusions. A business person using a clock hours away from the correct time can miss scheduled appointments.
Prior art paging systems which transmit time of day information suffer from several problems. First, a pager entering a new time zone resets its clock to correspond to the time of day signal of the new time zone. However, a person cannot choose to operate their clock several minutes fast as many people desire. Second, in order to transmit the time of day signal, transmitters must be able to guarantee that the transmission of the time of day signal is in coincidence with the accurate time of day. This can become an enormous problem when retrofitting the time signals into the existing queuing structure for messages within a paging terminal. Third, the time of day signals consume valuable information channel capacity which could otherwise be used for the transmission of paging messages. And fourth, the time signal must be transmitted in every location that the business person travels. This can be a difficult requirement to impose on nation wide systems operating in conjunction with independently operated local paging systems.